System of constant-current distribution.



P. H. THOMAS. SYSTEM OF CONSTANT CURRENT DISTRIBUTION.

APPLICATION FILED JAN-11,1916.

1,235,742. I Patented Aug. 7,1917.

J'I I 5 20 17 o o Md g J 4 \3: 1 v a x21 7 40 0 77 1;; zv mvron I 8V ATTORNEY- PERCY H. 'rnoraas, or UPPER MoNrcLAI'a, NEW JERSEY, AssIoNon, 'ro coornn irnwrrr nnnornrooorareiw, or HOBGKEZN, new JERSEY, A coaronnrron or NEW JnnsEY.

SYSTEM OF CONSTANT-CURRENT DISTRIBUTION.

Original application filed March 22, 1913, Serial No. 756,074. Divided and this application fi led 1916. Serial No. 71,395.

To all whom it may concern:

Be it known that I, PERoY'l-I. THOMAS, a citizen of the UnitedStates and resident of Upper Montclair, county 0t Essex, State of New Jersey, have invented certain new and useful Improvements in Systems of Constant Current Distribution, of which the following. is a specification.

Specification of Letters Patent.

Myinvention relates to the construction.

of mercury vapor devices for series operation and more particularlyfor operation on a constant current circuit. However, insome cases my invention is useful in connection with other supply circuits. These mercury vapor devices, comprising exhausted containers with anodes and vaporizable cathodes therein, have a general characteristic in accordance with which the voltage drop on the device tends to increase rapidly with an increase in current throughout a considerable portion of its operating range. In other words in such a device the current flow tends to remain approximately constant,

while the voltage drop varies greatly up and down according to the variations in the potential of the supply. This characteristic renders series operation of these devices unstable and unsatisfactory where no means are provided for controlling variations. My present invention provides for the neutralizing or overcoming or compensating for this characteristic of the mercury vapor apparatus which tends to disturb series operation.

If a number of these mercury vapor lamps are placed in series on a constant current circuit and certain of them become heated more than the others, thus tending to take more voltage, this overheating tendency can be corrected or balanced it means can be found for reducing the heat generated in the device. For since it naturally has a definite heat radiating power, any lessening of the heat generated within it will reduce the temperature at which it operates and thus. the pressure of the vapor and the resistance of the device. In my invention I accomplish this result by changing the length of vapor path in accordance with changes in the vapor pressure or the resistance of the lamp, thus automatically interliuking the disturbing cause andthe remedial means. If such adjusting system be applied to each of a number of serially operated mercury vapor devices on a constant current circuit which Patented Aug. 7, 1917.

January 11,

can be made automatically to absorb its own proper share of the voltage available without robbing the others andwithout itself developing an excessivevapor pressure, the difiiculties already pointed out will be 'overcome. This method is'broadly applicable to vapor electric devices andmay be carried out in a number of ways. I

For instance, I have illustrated my invention 1n the accompanying drawings, Figure 1 showing such a systemwith a diflerential shunt operating magnet; and Fig. 2 showing a modification. I11 the first figure, wherein I have illustrated the application to a relatively conlifting core, 19 a link connecting the core,

18, to the yoke 17 20 a counterweight, 21 a stop limiting movement of the yoke 17, 22 a series tilting coil, 23 a shunt coil tending to weaken the influence of the coil 22 and 24 a resistance in series with the shunt winding 23. At 25 I have shown aseries resistance which may be cut out by closing the switch '26 when desiredi In the initial position as shown, the mercury' i is in contact with the anode 3. When this device is con nected in a constant current circuit, current initially traverses the mercury between the electrodes, excites the winding 22-thus raising the yoke 17 and breaking the mercury connection between the electrodes. this period no current has been flowing in the shunt coil 23 since it has been short circuited by the mercury. As the device warms up, however, the voltage drop on the tube increases and current appears in the shunt coil 23. As long as the voltage drop, however, is below normal the coil, 22, still has power enough to hold the yoke, 17, against the stop, 27, but if the voltage drop tends to become excessive, the coil, 23, so weakens the pull of the 0011,22, as to drop the yoke,

17, and. the mercury, 4, which has been in the dotted position shown at 4 takes an 1ntermediate position such as that shown at 4 thus reducing the length of the vapor path and lessening the heat generated in the device, which will tend to correct the overheating of the vapor path. Similary varying positions can be taken by the mercury, 4, corresponding to the various conditions of operation. Should the device drop out, for any reason, the container and yoke 17 will return to the stop 21 and the starting operations will be repeated as already described.

The arrangement of the center of gravity with regard to the knife edge support, if de sired, may be adjusted as described in connection with Figs. 2 and 3 of my Patent 1,168,439, dated January 18th, 1916.

In 2 I have shown a still. different embodiment of the invention, in which the normal position of rest is with the mercury at the anode end. Here, the device 1 is held in a yoke 6 to which is secured a magnetic core, 8 through a slot and pin connection, shown at 10 and 11, for limiting the motion of said magnetic core.

The two magnet cores, 8 and 41, tend to lift the device on opposite ends of the knife edge support, 5. The core, 41, is attached to the lamp through the link 42. The core, 8, is magnetized by the coil, 34, which isconnected in shunt to the lamp through the resistance, 44. The core, 41, is magnetized by the coil, 35, which is connected in series with the anode lead. In shunt to the device, I use a circuit, 43, containing a resistance, 36, and the cut-out, 40. This cutout is closed when the lamp tube which carries the upper half of the contact, 40, drops down upon the lower half of the contact, 40. This downward motion of the tube is limited when the cut-out arm reaches the stop, 37. The cutout, 40, is so devised as not to open the circuit the instant the lamp starts to operate, but at some later period. This action is secured through the use of a counter weight, 39, on the opposite end of the arm of the cut-out, 40. The lower half of the cut-out, 40, will follow the upper hall with the rising of the tube until the cut-out arm strikes the stop, 38, when the cut-out will be opened. I use a resistance, 44, in series with the winding, 34, to control the shunt current.

The operation is as follows: W hen a constant current is established in the main circuit, it traverses the shunt, 43, the resistance, 36, the cut-out, 40, and passes thus through the anode lead out to the line through the coil This causes a tiltingof the device through the core, 41, and the streaming of the mercury to make connection with the cathode, 4. When this connection is made, current will be established through the die vice in view of the resistance, 36. This establishment oi current through the tube will,

however, not stop the tilting which will pro ceed. The cut-out, 40, will ultimately open the circuit, 43, when the cut-out arm reaches the stop, 38. The current will continue to flow and warm up the tube until current is established in shunt containii'ig the resistance, 44, and the coil, 34, and as normal voltage is reached, the core, 8, will raise the cathode, 4, slightly until the mercury approaches nearer to the anode, thus cutting down the heat generated in the device and securing regulation, as already described. It will be understood that during normal operation, the tube is maintained at such angles that the mercury of the cathode ranges from the right hand end of the cathode chamber to a point about the middle of the cathode chamber.

In any of the figures shown, I contemplate the use of any of the mechanical or magnetic eXpedients shown in the other figure. For example in Fig. 1 any of the expedients used in connection with the other figure.

Furthermore I may use a mercury anode in any desired case, or a solid anode, as may be desired. I have not shown specific means .for controlling the pull-distance curves of these magnets since the means of controlling such pull curves are well known.

lNhile Ihave shown forms of containers in some cases suitable for light giving purposes, or for the production of useful radiations, I do not wish to limit my invention to such particular uses of vapor electric device, but may apply the principles thereof to almost any form or embodiment.

The apparatus shown in these figures may be applied to the high pressure mercury vapor lamps with quartz containers to which they are well adapted.

I do not wish to limit my invention to the particular embodiments herein shown, which are merely illustrative, but consider that any similar system utilizing equivalent means to produce the same result come Within its i scope. Other materials than mercury may be utilized for the cathode andother materials than tungsten, for egiample mercury itself, may be used for the anode. I may, of course, supply dash pots or Vibration suppressors to prevent undue violence in the operation of the automatic circuits and I may otherwise apply various expedients well known for adjusting and controlling the various elements herein described and shown. Folexample, I may use a dash-p0t, 100, as shown in Fig. 1.

This application is a division of my application Serial Number 756,074, filed March 22nd, 1913.

I claim as my invention:

1. In a system of electrical distribution, the combination with a constant current suply, a movable vapor apparatus comprising an exhausted container, electrodes therein,

the container, means for movably mounting said device on the cathode side of the center of gravity, means for starting said device from the main current in shunt thereto, means for moving said device for regulating purposes forming a shunt circuit thereto and means operated by the main current for shifting the balance of said device to the cathode side of said mounting.

2. In a, system of electrical distribution, the combination with a constant current supply, a movable vapor apparatus comprising an exhausted container, electrodes therein, one of which is adjustable with movement of the container, means for movably mounting said device on the cathode sideof the center of gravity, means for starting said device from the main current passing in shunt thereto, means for moving said device for regulating purposes forming a shunt circuit thereto and means operated by the main current for shifting the balance of said device to the cathode side of said mounting and means for cutting out said starting means.

. Signed at New York, in the county of New York and State of New York, this eighth day of January, A. D. 1916.

PERCY H. THOMAS. Witnesses:

THos. H.- BROWN, HAROLD B. Woonwm. 

